Recent evidence suggests that the receptors for thyrotropin, tetanus toxin, and interferon are composed of both a glycoprotein and a ganglioside. One effect of the interaction of each of these ligands with its receptor components is an alteration in membrane potential and ion fluxes. The mechanism and effects of these agents on membrane potential and ion fluxes, in particular on calcium transport mechanisms, has been further characterized. With the recent development and availability of monoclonal antibodies to the receptor components of these agents, an examination of the relationship of receptor-effector interactions to the transport of ions and solutes across the cell membrane is now possible.